web2py is not an AJAX framework but it works with AJAX frameworks. For examples scriptaculous works great with web2py. You may also use Web2py controllers to handle JSON request/response messages. Web2py also come with some a view called "web2py_ajax.html" included by "layout.html" that provides popup, collapse, fade effects and an "ajax" function that performs can asynchronous web2py connections (see the examples).